Page 41 - Geography for Secondary Schools Student’s Book Form One

Geography for Secondary Schools
Student’s Book Form One
Since longitude lines meet at the poles, the Great circles
distance between degrees of longitudes A Great circle is any circle that divides the
becomes progressively less towards the Earth into two equal spheres (Figure 3.15).
poles (Figure 3.14). The equator and the Greenwich Meridian

are both great circles. Similarly, all other
meridians are also great circles. The equator,
FOR ONLINE READING ONLY
45°E on the other hand, is the only latitude that
is a great circle.

0° 45°E A

45°E E

45°E
C D
Figure 3.14: Determining longitudes

Generally, when locating or finding position F
of a place using latitudes, you start with the
latitudes followed by longitudes. B
Great Circles Globe

Activity 3.9 Figure 3.15: Great circle

(a) Take the world map or globe, and Great circles are important in our daily life.
find your country on it. They are used in navigation and aviation.
(b) Study the latitude and longitude to They are used to plot shore routes for ships
identify the position of your country. crossing the oceans to save fuel and time. In

aviation, pilots use great circles to mark the
Exercise 3.6 shortest path. In general, great circles are
the shortest routes between any two places
1. Explain the relationship between far apart on the earth’s surface.
longitudes and time.

2. Why does the distance through the Importance of latitudes and longitudes
Equator from West to East differ from The usefulness of latitudes and longitudes
that measured from North Pole to are as follows:
South Pole? (a) Latitudes determine climatic variations.

3. Why are parallels different from For example, the temperature
meridians? decreases from the Equator towards
the poles.

35

18/10/2024 18:32:36
GEOGRAPHY (F1) TO PRESS.indd 35
GEOGRAPHY (F1) TO PRESS.indd 35 18/10/2024 18:32:36